Explanation:

Let’s get into it:

- Order 12, Rule 3: This one actually talks about “admission of documents” in the Code of Civil Procedure (CPC), not the form of notice. So, it's not the right pick.

- Order 4, Rule 13: This rule isn’t about the form of notice either; it generally deals with the register of suits.

- Order 6, Rule 10: This is all about the “form of pleadings”—how documents submitted to the court should be formatted, not about notice.

- Order 13, Rule 22: This deals with the “transmission of documents” especially between courts but not about notices.

Correct Answer: Order 6, Rule 10 — This rule specifically addresses the form of notice in pleadings under CPC.

So, if you picked Order 6, Rule 10, you nailed it.